New draft: Implementation of a General Purpose Programming Language with Dependent Types

Many components of a dependently typed programming language are by now well understood, for example the underlying type theory, type checking, unification and evaluation. How to combine these components into a realistic and usable high level language is, however, folklore, discovered anew by succesive language implementations. In this paper, I describe the implementation of a new dependently typed functional programming language, Idris. Idris is intended to be a general purpose programming language and as such provides high level concepts such as implicit syntax, type classes and do notation. I describe the high level language and the underlying type theory, and present a method for elaborating concrete high level syntax with implicit arguments and type classes into a fully explicit type theory. Furthermore, I show how this method, based on a domain specific language embedded in Haskell, facilitates the implementation of new high level language constructs.

There’s still some polishing to do, but comments on the content, form, and so on, would be most welcome. Enjoy!